Early production:
0510572 I-0593 pre-'A', ROM 3.
052xxxx I-0593 pre-'A', ROM 4*
0608697 I-0693 pre-'A', ROM 8.0
Later early production:
0615716 I-0693 'E', ROM 10.0
0605463 I-0693 'H', ROM 10.0
Production:
0710606 I-0793 'F', ROM 10.0
0873670 I-0893 'K', ROM 16.0
25069403 I-1194 'Q', ROM 18.0